The invention relates to a method of preparing solid radioactive or toxic waste for long-term storage, and more particularly to a method of combining such waste with a hardenable binding agent.
In known processes for preparing mixtures of a radioactive or toxic waste and a hardenable binding agent to prevent escape of the active pollutants in the waste during the long-term storage thereof, the waste is contacted, under atmospheric pressure, with the binding agent while the latter is in a softened condition, after which the agent is permitted to harden to produce a solid waste-binder complex. Under such circumstances, the impregnation of the waste by the binding agent is not complete, and the matrix exhibits a porous structure which, when exposed to water penetration or the like during storage, has been susceptible to leaching and consequent atmospheric exposure of the active pollutant.
Moreover, in cases where the waste has a fine particulate structure, the particles thereof which are not impregnated by the binding agent can easily escape from the container that supports the waste and binder during the mixing operation.